In the long term evolution infrastructure, one proposal being studied is the use of control information in the MAC-PDU header. This can be used, for example, with discontinuous reception (DRX) of user equipment in an LTE_Active state. The 3GPP TSG-RAN Working Group 2 proposal R2-063081 proposes that regular DRX configuration be signaled by radio resource control (RRC) protocol and that temporary DRX configuration is signaled by Medium Access Control (MAC) signaling.
A problem with the sending of control information in the MAC-PDU header is due to HARQ feedback errors. In particular, when the enhanced Node B (eNB) misinterprets a NACK as an ACK for the downlink MAC data. In particular, with in band DRX parameters which configure a shorter DRX value than that of the already assigned DRX, the UE would miss subsequent downlink MAC data as sent from the eNB.